JPH09229246A - Synthetic resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a bent pipe and make a piping work easier by removably fitting a coil in a spiral recess along the axial direction on the outer surface of the pipe comprising an inner layer made of a soft synthetic resin and an outer layer stuck to the inner layer only from the recess to which flexibility needs to be given in the whole length of the pipe. SOLUTION: A straight pipe A comprises an inner layer 2 formed by bonding the neighboring edges of a spirally wound tape made of a soft synthetic resin to each other and an outer layer 3 formed by a strip 4 made of hard synthetic resin which is spirally wound along the outer surface of the inner layer 2 and is S-shaped in a section and has both edges formed in parallel bent tip ends 4a, 4a which are opposite in direction, wherein the neighboring bent tip ends 4a, 4a are engaged with each other such that they can be moved in the axial direction of the pipe. A bent pipe is made by removing a coil 6 from a recess 5 in the outer layer of the straight pipe A in desired length by hand or with a tool, whereby the strip 4 is returned to a state where the strip can be freely moved in the axial direction of the pipe and the synthetic pipe has flexibility at this portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible pipe that can be used as a pipe, for example, a drain pipe as a drainage facility in an elevated portion of a highway.

[0002]

2. Description of the Related Art Conventionally, a plurality of vertical or horizontal straight pipe drainage pipes are appropriately connected to an elevated portion of an expressway to guide rainwater gathered in an overhead girder or legs to a drainage pit of a road surface to sewer. Used by being connected by a device.

[0003]

However, a plurality of straight tubular drainage pipes must be connected by bending pipes or other connecting devices depending on the site, and the construction work is troublesome. It was In particular, when the pipe is installed in a complicated place at the bend, the work becomes more complicated and the work is inefficient. Therefore, in the present invention, although it is a single tubular body, it is possible to have a straight tubular portion with limited flexibility and a flexible tubular portion in an arbitrary portion in the longitudinal direction thereof. It is an object to provide a synthetic resin pipe.

[0004]

In order to solve the above-mentioned problems, in the present invention, an inner layer made of a soft synthetic resin and having a substantially smooth inner peripheral surface, and an outer layer of the inner layer made of a hard synthetic resin and having a substantially S-shaped cross section. -Shaped strips are formed by superposing the adjacent side edges in a non-adhesive state, spirally winding them, and adhering to the inner layer, and a spiral formed on the outer surface of the outer layer along the axial direction. A tubular body and a coil that restricts the flexibility of the tubular body by being removably fitted in the concave portion, and the coil is attached only to the portion of the entire length of the tubular body where flexibility is desired. The means is to give flexibility to an arbitrary length portion by removing it from the concave portion. Also,
An extruded soft synthetic resin tape is spirally wound and its side edges are bonded together to form an inner layer, and a hard synthetic resin strip extruded at the same time as the soft synthetic resin tape is spirally wound. It is possible to bond the formed outer layer and to fit the coil wound spirally at the same time as the above-mentioned strip into the space of the recess formed between the adjacent strips so as not to adhere to the above-mentioned strip. The means is to form a tubular body with limited flexibility.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a synthetic resin pipe according to the present invention will be described below with reference to the drawings. FIG. 1 shows an outline of a synthetic resin pipe 1 according to the present invention, in which a straight pipe portion A that is not bent due to a limited flexibility of a tubular body and a flexible pipe portion B that is bendable has a length. Formed continuously in the direction.

As shown in FIG. 2, the straight pipe portion A is formed by spirally winding a tape made of a soft synthetic resin (for example, a soft vinyl chloride resin) and joining adjacent side edges of the wound tape. A series of integrally formed inner layers 2, and a hard synthetic resin formed along the outer peripheral surface of the inner layer 2 on bent tip portions 4a, 4a having a substantially S-shaped cross section and opposite ends in parallel. For example, a strip 4 made of a hard vinyl chloride resin is spirally wound, and the adjacent bent tip end portions 4 of the strip 4 wound are wound.
a and 4a are overlapped with each other and are engaged with each other by movably engaging with each other in the tube axial direction to be connected. An uneven portion is formed along the. The inner layer 2 and the outer layer 3 are formed by simultaneously and extruding a soft synthetic resin tape and a hard synthetic resin strip 4 which are spirally wound and adhered on a tubular body molding shaft (not shown). Further, the hard synthetic resin strips 4 are in a non-adhered state by, for example, being wound while blowing cooling air between the adjacent strips 4 so that adjacent strips do not adhere to each other.

In the space 5 of the concave portion on the surface of the outer layer 3, for example, a coil 6 made of a synthetic resin material such as a polyolefin which does not heat-bond to the strip is simultaneously extrusion-molded while being filled and fitted to the strip 4. The synthetic resin pipe 1 is prevented from bending by blocking the movement of the plastic pipe in the axial direction of the pipe, thereby limiting its inherent flexibility. The coil 6 may be detachably fitted into the space 5, and may be made of hard vinyl chloride extruded at a temperature low enough not to adhere to the strip 4, and may already be extruded. Alternatively, a strip made of synthetic resin or a hard material other than synthetic resin may be used to spirally wind and fit into the space 5 during the molding process of the synthetic resin pipe 1. Alternatively, after the synthetic resin tube composed of the inner layer and the outer layer is once molded, the coil formed of the above-mentioned various materials may be detachably filled and fitted into the space of the outer layer recess in a separate step.

FIG. 3 shows a curved pipe portion B. The coil 6 is provided with the recessed space 5 of the outer layer 3 by an arbitrary length from the tubular body formed into the structure of the straight pipe portion A shown in FIG. It has a structure in which it is removed and removed by an appropriate means such as human power or a tool, and since the strip 4 is restored to the state of being movable in the pipe axis direction, the synthetic resin pipe 1 has flexibility in this portion. doing.

FIG. 4 shows another embodiment of the straight pipe portion A, in which projections 8 for preventing the coil 6 from coming off are provided at both ends of the strip 4 forming the convex portion 7 of the outer layer 3 to form a concave portion. The coil 6 fitted in the space 5 is completely designed so as not to fall off during use. The projections 8 and 8 in this embodiment are intended to prevent the coil 6 from coming off temporarily, and the coil 6 can be freely removed by pulling it out with a little strong force, which hinders the formation of the curved tube portion. is not.

[0010]

According to the first aspect of the present invention, a flexible curved pipe portion is provided in a necessary portion by removing the coil fitted in the outer layer concave portion even though it is a single synthetic resin pipe. Since it can be formed, it is possible to perform curved pipe construction suitable for the site without preparing a curved pipe separately, and the construction work can be done easily and in a short time. In addition, the straight pipe part where the coil is not removed has a structure that does not easily bend, so it is sufficient to place the straight pipe part in the part where you want to maintain a straight piping state without the need of flexibility, according to the situation of the construction site. There is an advantage that the curved pipe portion and the straight pipe portion can be arbitrarily configured.

According to the second aspect of the present invention, the coil is formed by simultaneously spirally winding the soft synthetic resin tape forming the inner layer, the hard resin strip forming the outer layer, and the coil. There is an advantage that the tube body before removal can be efficiently manufactured.

[Brief description of drawings]

FIG. 1 is a schematic view showing the entire synthetic resin pipe of the present invention.

FIG. 2 is a cross-sectional view of a main portion showing a straight pipe portion of a synthetic resin pipe.

FIG. 3 is a cross-sectional view of an essential part showing a curved pipe portion of a synthetic resin pipe.

FIG. 4 is a sectional view of a main portion showing another embodiment of the straight pipe portion.

[Explanation of symbols]

 1 ... Synthetic resin tube 2 ... Inner layer 3 ... Outer layer 4 ... Strip 5 ... Recessed space 6 ... Coil 7 ... Convex section 8 ... Protrusion A ... Straight tube section B ... Curved tube section

Front page continuation (72) Inventor Jouji Hattori, 6th Danyo, Kakegawa, Shizuoka Prefecture, Tigers Polymer Co., Ltd. Shizuoka factory (72) Inventor Yoshiki Yoshitomi, 6th, Tanyo, Kakegawa city, Shizuoka Tigers Polymer, Shizuoka factory

Claims (2)

[Claims] 1. An inner layer made of a soft synthetic resin and having a substantially smooth inner peripheral surface, and a cross section S made of a hard synthetic resin on the outer periphery of the inner layer.
The letter-shaped strip was formed by superposing the adjacent side edges in a non-adhesive state, spirally winding them, and adhering to the inner layer, and the outer surface of the outer layer along the axial direction. A coil comprising a coil which is removably fitted into a spiral recess to limit the flexibility of the tubular body, and the coil is provided only for a portion of the entire length of the tubular body to which flexibility is desired. A flexible pipe made of synthetic resin, characterized in that flexibility is imparted to an arbitrary length portion by removing from the recess. 2. An inner layer formed by spirally winding an extruded soft synthetic resin tape and adhering its side edges to each other, and a strip made of a hard synthetic resin extruded simultaneously with the soft synthetic resin tape. A coil wound in a spiral shape at the same time as the outer layer is adhered, and a coil wound in a spiral shape at the same time as the above-mentioned strip is not adhered to the above-mentioned strip, and is formed in a space of a concave portion formed between adjacent strips. The synthetic resin pipe according to claim 1, which is fitted to form a pipe body having limited flexibility.